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Date:   Wed, 6 Jun 2018 09:39:29 +0530
From:   Viresh Kumar <viresh.kumar@linaro.org>
To:     Arnd Bergmann <arnd@arndb.de>
Cc:     "Rafael J. Wysocki" <rjw@rjwysocki.net>,
        Ilia Lin <ilialin@codeaurora.org>, linux-pm@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] cpufreq: kryo: allow building as a loadable module
Message-ID: <20180606040929.tksvznlmb3ogtgur@vireshk-i7>
References: <20180605114453.1381941-1-arnd@arndb.de>
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On 05-06-18, 13:44, Arnd Bergmann wrote:
> Building the kryo cpufreq driver while QCOM_SMEM is a loadable module
> results in a link error:
> 
> drivers/cpufreq/qcom-cpufreq-kryo.o: In function `qcom_cpufreq_kryo_probe':
> qcom-cpufreq-kryo.c:(.text+0xbc): undefined reference to `qcom_smem_get'
> 
> The problem is that Kconfig ignores interprets the dependency as met
> when the dependent symbol is a 'bool' one. By making it 'tristate',
> it will be forced to be a module here, which builds successfully.
> 
> Fixes: 46e2856b8e18 ("cpufreq: Add Kryo CPU scaling driver")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>  drivers/cpufreq/Kconfig.arm | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
> index c7ce928fbf1f..52f5f1a2040c 100644
> --- a/drivers/cpufreq/Kconfig.arm
> +++ b/drivers/cpufreq/Kconfig.arm
> @@ -125,7 +125,7 @@ config ARM_OMAP2PLUS_CPUFREQ
>  	default ARCH_OMAP2PLUS
>  
>  config ARM_QCOM_CPUFREQ_KRYO
> -	bool "Qualcomm Kryo based CPUFreq"
> +	tristate "Qualcomm Kryo based CPUFreq"
>  	depends on ARM64
>  	depends on QCOM_QFPROM
>  	depends on QCOM_SMEM

Okay, so we really need this to be a module. But the driver can't really work as
a module right now if we do this: insmod, rmmod, insmod. Because it doesn't free
resources at rmmmod and will fail on second insmod.

Because what you are fixing is a critical build error, we better get it merged
right now.

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>

But Ilia needs to cook another patch to add the module removal code for the
driver and mark your patch's commit id in the fixes tag.

-- 
viresh